Agency: Dolphins' cause of death unclear, human role likely

HONOLULU (AP) — A federal report on three dolphins that died shortly after Navy ships used sonar nearby has found the animals were likely affected by the same human event.

The report by the National Marine Fisheries Service said experts weren't able to determine what caused the death of the animals in Southern California in late October.

But a panel of five experts could not rule out naval or other human activities.

The fisheries service said it and the Navy are working to provide the panel with additional information requested by the experts. It's not clear when the agency will complete its review of the deaths.

The fisheries service posted its report online last month as part of a settlement with environmental groups from Hawaii and elsewhere. They filed a lawsuit challenging Navy sonar use.

The first two dolphins were found at Imperial Beach and Silver Strand Beach on Oct. 21. The agency said the Navy verified it used mid-frequency active sonar during training within 80 nautical miles of the stranding sites on Oct. 19 and Oct. 20.

The third dolphin was found badly decomposed in Coronado on Oct. 31.

The report said the dolphins showed no sign of infection. This, the timing and the location of the strandings all indicated the dolphins were affected by a human event. There was no evidence the dolphins had a run-in with fishing gear.

David Henkin, an attorney for Earthjustice, which represented environmental groups in the lawsuit, said it's important that the agency find out quickly what happened to the dolphins.

"They might conclude there are Navy activities happening off of San Diego that are posing an unexpected risk of killing dolphins," Henkin said. "And both under the settlement, and under the Marine Mammal Protection Act, they need to do something about that."